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/***********************license start***************
 * Copyright (c) 2003-2010  Cavium Networks (support@cavium.com). All rights
 * reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.

 *   * Neither the name of Cavium Networks nor the names of
 *     its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written
 *     permission.

 * This Software, including technical data, may be subject to U.S. export  control
 * laws, including the U.S. Export Administration Act and its  associated
 * regulations, and may be subject to export or import  regulations in other
 * countries.

 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, THE SOFTWARE IS PROVIDED "AS IS"
 * AND WITH ALL FAULTS AND CAVIUM  NETWORKS MAKES NO PROMISES, REPRESENTATIONS OR
 * WARRANTIES, EITHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, WITH RESPECT TO
 * THE SOFTWARE, INCLUDING ITS CONDITION, ITS CONFORMITY TO ANY REPRESENTATION OR
 * DESCRIPTION, OR THE EXISTENCE OF ANY LATENT OR PATENT DEFECTS, AND CAVIUM
 * SPECIFICALLY DISCLAIMS ALL IMPLIED (IF ANY) WARRANTIES OF TITLE,
 * MERCHANTABILITY, NONINFRINGEMENT, FITNESS FOR A PARTICULAR PURPOSE, LACK OF
 * VIRUSES, ACCURACY OR COMPLETENESS, QUIET ENJOYMENT, QUIET POSSESSION OR
 * CORRESPONDENCE TO DESCRIPTION. THE ENTIRE  RISK ARISING OUT OF USE OR
 * PERFORMANCE OF THE SOFTWARE LIES WITH YOU.
 ***********************license end**************************************/







/**
 * @file
 *
 * Module to support operations on bitmap of cores. Coremask can be used to
 * select a specific core, a group of cores, or all available cores, for
 * initialization and differentiation of roles within a single shared binary
 * executable image.
 *
 * <hr>$Revision: 49448 $<hr>
 *
 */

#include "cvmx-config.h"
#include "cvmx.h"
#include "cvmx-spinlock.h"
#include "cvmx-coremask.h"


#define  CVMX_COREMASK_MAX_SYNCS  20  /* maximum number of coremasks for barrier sync */

/**
 * This structure defines the private state maintained by coremask module.
 *
 */
CVMX_SHARED static struct {

    cvmx_spinlock_t            lock;       /**< mutex spinlock */

    struct {

        unsigned int           coremask;   /**< coremask specified for barrier */
        unsigned int           checkin;    /**< bitmask of cores checking in */
        volatile unsigned int  exit;       /**< variable to poll for exit condition */

    } s[CVMX_COREMASK_MAX_SYNCS];

} state = {

    { CVMX_SPINLOCK_UNLOCKED_VAL },

    { { 0, 0, 0 } },
};


/**
 * Wait (stall) until all cores in the given coremask has reached this point
 * in the program execution before proceeding.
 *
 * @param  coremask  the group of cores performing the barrier sync
 *
 */
void cvmx_coremask_barrier_sync(unsigned int coremask)
{
    int i;
    unsigned int target;

    assert(coremask != 0);

    cvmx_spinlock_lock(&state.lock);

    for (i = 0; i < CVMX_COREMASK_MAX_SYNCS; i++) {

        if (state.s[i].coremask == 0) {
            /* end of existing coremask list, create new entry, fall-thru */
            state.s[i].coremask = coremask;
        }

        if (state.s[i].coremask == coremask) {

            target = state.s[i].exit + 1;  /* wrap-around at 32b */

            state.s[i].checkin |= cvmx_coremask_core(cvmx_get_core_num());
            if (state.s[i].checkin == coremask) {
                state.s[i].checkin = 0;
                state.s[i].exit = target;  /* signal exit condition */
            }
            cvmx_spinlock_unlock(&state.lock);

            while (state.s[i].exit != target)
                ;

            return;
        }
    }

    /* error condition - coremask array overflowed */
    cvmx_spinlock_unlock(&state.lock);
    assert(0);
}